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For the Medify MA-40 vs MA-50, ignore the 1,793-square-foot and 2,640-square-foot marketing numbers and look at smoke CADR instead. In this case, that means 239 CFM against 352 CFM — and that gap, not the headline coverage, is what actually tells you which unit fits your room.
The reason this comparison is messier than it should be is that Medify has quietly revised both models. Older reviews still describe MA-50 units with UV-C and auto sensing, and MA-40 units with sensors that the current generation no longer carries. If you size your room from a stale comparison, you can end up with the wrong machine.
This guide compares the current specs side by side, converts both to the same real-world cleaning standard, and shows exactly where the MA-40 starts to make less sense and the MA-50 becomes the right call. I'll also cover noise, filters, and the layout caveats that matter more than any square-foot claim.
This is for you if you're deciding between these two Medify units for a bedroom, living room, open kitchen, studio, or large open space — and you want the one that actually exchanges your air often enough without running flat-out all day.
Quick Verdict
| Medify MA-40 | Medify MA-50 V3.0 | |
|---|---|---|
| Smoke CADR | 239 CFM | 352 CFM |
| Real room at 4 ACH | 448 ft² | 660 ft² |
| Real room at 5 ACH | 358.5 ft² | 528 ft² |
| Fan speeds | 3 + sleep | 4 + sleep |
| Best for | Bedrooms and living spaces up to roughly 400 ft² | Open rooms around 500–650 ft², or when you want headroom |
| Check price | Check current price on Amazon | Check current price on Amazon |
Which Versions Are We Comparing?
Medify's current MA-40 is the model you'll find on the active Amazon listing, with a maximum smoke CADR of 239 CFM and 448 ft² of coverage at 4 ACH. Some older content still cites roughly 380 m³/h and 840-square-foot coverage for the MA-40, but that describes previous hardware and should not be used for sizing.
The current MA-50 is explicitly branded MA-50 V3.0. It produces 352 CFM of smoke CADR, covers 660 ft² at 4 ACH, and — importantly — does not list UV-C on Medify's current product page. That's a real disconnect from legacy MA-50 reviews, many of which describe a UV-equipped unit. If you're reading a comparison that mentions UV-C on the MA-50, you're almost certainly looking at an older version.
What didn't change is that neither current headliner has an automatic air-quality sensor. Medify removed sensors from the MA-40 line starting with the 2.0 revision because the clean zone immediately around the unit caused the motor to drop speed prematurely. So don't buy either current model expecting PM2.5-driven auto mode — size and speed selection are still on you.
Airflow & Real Room Coverage — MA-40 vs MA-50
The biggest mistake people make with either unit is reading the largest advertised number as a normal room recommendation. A headline like "covers up to 1,793 ft²" is based on one air change per hour, which is a light cleaning pass, not the 4.8–5 ACH most allergy and smoke applications actually call for. If you want frequent, meaningful air exchange, the realistic numbers are much smaller.
Here is the same-basis ladder Medify publishes for its current lineup, using an 8-foot ceiling:
| Model | Smoke CADR | 4 ACH coverage | 5 ACH coverage | Medify/AHAM 4.8 ACH |
|---|---|---|---|---|
| MA-14 | 57 CFM | 107 ft² | 85.5 ft² | 89 ft² |
| MA-25 | 110 CFM | 206 ft² | 165 ft² | 172 ft² |
| MA-40 | 239 CFM | 448 ft² | 358.5 ft² | 373 ft² |
| MA-50 V3.0 | 352 CFM | 660 ft² | 528 ft² | 550 ft² |
| MA-112 | 594 CFM | 1,114 ft² | 891 ft² | 928 ft² |
So the practical boundary is fairly clean: for a genuine 4–5 ACH target, the MA-40 is a roughly 360–450-square-foot machine, while the MA-50 stretches into the 500–650-square-foot range. The MA-50's 47% higher smoke CADR is the whole story.
There are two more qualifiers you can't ignore.
First, ceiling height. All of these numbers assume an 8-foot ceiling. A 10-foot ceiling in the same footprint increases air volume by 25%, which effectively shrinks the cleanable floor area unless you move up a size.
Second, walls matter. One MA-50 cannot reliably clean a two-bedroom apartment through closed doors; it only works on the open air volume it's actually in. If your "large room" is really several separated rooms, I'd rather see you run two appropriately sized units than one oversized purifier behind a hallway. That's also why the air purifier room size guide is worth keeping open while you shop.
Noise and Everyday Operation — MA-40 vs MA-50
The noise story here is the opposite of "the bigger unit is always louder."
The MA-40's official figures are 40.5 dBA in sleep/speed 1, 50.3 dBA at speed 2, and 53.3 dBA at maximum. It has a relatively high floor and a moderate ceiling.
The MA-50 V3.0 is much quieter at the bottom: 21.2 dBA at speed 1, 21.7 dBA in sleep, 32.3 dBA at speed 2, and 42.7 dBA at speed 3 — but it jumps to 60.6 dBA at maximum. If you mainly run a purifier in a bedroom at night, the MA-50 has a serious low-speed advantage. If you expect to run it at full tilt in a living room during the day, the MA-40 actually tops out about 7 dB quieter.
The practical takeaway is straightforward: MA-50 on low or medium is often the better bedroom experience, while MA-40 at max is the more tolerable "I need everything now" mode in a shared space. Just don't assume the MA-50's higher airflow automatically means more noise all the time. The noise levels explainer breaks down why a few decibels on paper can feel much louder in a hard-surfaced room.
Filtration, Filters, and Running Costs
Both current models use the same basic architecture: a washable-looking pre-filter, a HEPA particulate stage, and an activated-carbon stage. Medify does not publish the actual carbon mass for either unit, so don't interpret either one as a heavyweight VOC machine just because it has a carbon layer. They're primarily particulate purifiers.
One thing to watch: Medify's own materials reference HEPA, H13, and H14 configurations across its site, and the exact filter grade can vary by SKU. For everyday particle removal, chasing the highest HEPA class is rarely the right lever — a more restrictive filter can reduce airflow if the motor isn't sized for it. Matching the correct replacement filter to your specific unit matters more than the marketing letter.
Filter life also differs. The MA-40 is rated for roughly 3,000 operating hours, or 4–5 months of typical continuous use. The MA-50 V3.0 is rated for about 2,500 hours, or 3–4 months. Neither is close to a year, which is worth budgeting for before you buy — Medify filters are consumables, and the filter replacement guide will help you stay ahead of the indicator rather than react to it.
Feature Check: Auto Mode, UV-C, and What Changed
If you're coming from a comparison article written a few years ago, expect two surprises.
No auto mode. The current MA-40 has three fan speeds plus sleep, a 0–8-hour timer, touch controls, child lock, and a filter indicator. The current MA-50 V3.0 has four speeds plus sleep, a 2–12-hour timer, dimmer, child lock, and filter indicator. Neither one has a continuous PM2.5-driven auto mode, and neither should be bought as if it does. You set the speed, and the machine holds it.
No integrated UV-C on the MA-50 V3.0. The V3.0 revision removed the UV stage that older MA-50 reviews describe. The MA-40 can still be ordered in some configurations with an optional UV light, and Medify lists an optional ionizer for the MA-40, but the current MA-50 is not a UV-equipped unit. UV can be useful in certain setups, but it does not add particle CADR — fan and filter do the cleaning work. If UV is a hard requirement for you, check the exact SKU before ordering, not the old review photo.
Head-to-Head Specs Comparison
| Spec | Medify MA-40 | Medify MA-50 V3.0 |
|---|---|---|
| Smoke CADR | 239 CFM | 352 CFM |
| Dust CADR | 231 CFM | 379 CFM |
| Pollen CADR | 240 CFM | 397 CFM |
| PM2.5 CADR | 235 CFM | 365 CFM |
| 4 ACH coverage | 448 ft² | 660 ft² |
| 5 ACH coverage | 358.5 ft² | 528 ft² |
| AHAM 4.8 ACH reference | 373 ft² | 550 ft² |
| Fan speeds | 3 + sleep | 4 + sleep |
| Speed CADR | 111.8 / 144.3 / 181.2 / 239 CFM | 19.0 / 90.6 / 159.5 / 352 CFM |
| Noise | 40.5 / 50.3 / 53.3 dBA | Sleep 21.7, 21.2 / 32.3 / 42.7 / 60.6 dBA |
| Timer | 0–8 hours | 2–12 hours |
| Air-quality sensor / auto mode | No | No |
| UV-C | Optional on some SKUs | Not listed on current V3.0 |
| Filter life | ~3,000 hours / 4–5 months | ~2,500 hours / 3–4 months |
| Rated power | 68 W | 70 W |
| Dimensions | 22 × 9.9 × 10.9 in | 21.18 × 9.65 × 9.65 in |
| Weight | 17.5 lb | 10–16 lb (source conflict) |
| Warranty | Limited lifetime | Limited lifetime |
| Check price | Check current price on Amazon | Check current price on Amazon |
Which Should You Buy?
Choose the Medify MA-40 if your actual room is roughly 400 square feet or smaller at typical ceiling height, and you want a mid-size unit that doesn't need to be run at maximum all day. It's still a capable particulate machine for a bedroom, home office, dorm, or compact living area. Its lower max-speed noise also makes it a bit more livable when you do push it hard.
Choose the Medify MA-50 V3.0 if your space is genuinely 500–650 square feet, you have an open kitchen-living layout, or you want real airflow headroom for smoke, pollen, or pet dander events. The higher CADR earns its keep in open environments, and its low-speed noise is excellent for overnight bedroom use — just know that cranking it to full output is loud.
If your room is meaningfully above 650 square feet at a 4–5 ACH target, neither unit is the clean answer. That's the territory where the MA-112 or two smaller units placed in separate zones start to make more sense. You can see how all of these fit into the broader lineup in the Medify complete guide.
One pricing note: street pricing on these two moves around enough that the bigger unit is not always the more expensive one at checkout. The MA-50 can land close to — or even under — the MA-40's typical selling price during promotions. Size your room first, then compare current prices rather than assuming more airflow always means a bigger bill.
Frequently Asked Questions
Q: Is the MA-50 always better because it has higher CADR?
Not necessarily. Higher CADR only helps if your room can use it. In a small bedroom, an MA-40 will already maintain strong air exchange without running at maximum. The MA-50's advantage shows up in larger open spaces, high-pollution loads, or when you want strong cleaning while staying on a lower, quieter fan setting.
Q: Can I use one MA-40 or MA-50 for a whole apartment?
Only if your apartment behaves like one open, well-mixed air volume. A purifier cannot pull air through walls and closed doors. In a two-bedroom apartment, you'll usually get better results from two smaller units than from one large unit in the living room.
Q: Does the current MA-50 have UV-C?
No. The current MA-50 V3.0 product page does not list UV-C. Older MA-50 reviews often describe a UV-equipped unit, which is why the revision matters. The MA-40 can be ordered with optional UV on some SKUs, so verify the exact configuration before buying if UV is important to you.
Q: Why do some older reviews list much bigger coverage numbers?
Two reasons. First, some older reviews are based on previous MA-40 and MA-50 hardware, not the current versions. Second, older comparisons often mix CFM and m³/h, or they repeat the largest 1-ACH marketing figure as if it were a normal room recommendation. Current Medify pages give the honest 4–5 ACH numbers, and those are much smaller.
Q: Should I buy the MA-50 and just run it on low for a small bedroom?
That can work well for noise, but don't assume "MA-50 on low" equals "MA-40 on high." The MA-50's speed 1 is only 19 CFM, and even speed 2 is 90.6 CFM. You'd need speed 3 — about 159.5 CFM — to approach MA-40's mid-range output. The MA-50's low-speed smoothness is a real benefit, but choose the room size first, then use the speed curve to match your nightly comfort.
Q: How often do filters need replacing?
Medify rates the MA-40 filter for roughly 3,000 operating hours, or 4–5 months, and the MA-50 V3.0 for roughly 2,500 hours, or 3–4 months. Replacement frequency depends on how many hours a day you run the unit and how dusty the room is, so treat the indicator as a starting point, not a countdown.
Conclusion
The Medify MA-40 vs MA-50 decision really comes down to one number: smoke CADR. At 239 CFM, the MA-40 is a legitimate 360–450-square-foot room purifier. At 352 CFM, the MA-50 V3.0 stretches comfortably into 500–650 square feet and gives you more headroom for open layouts and high-pollution spikes.
I'd pick the MA-40 for a standard bedroom or compact living space where moderate airflow is enough. I'd pick the MA-50 V3.0 for an open living-kitchen area, a larger primary bedroom where you want strong low-speed cleaning, or any room pushing past 450 square feet. Just remember that neither current model has auto sensing, and the V3.0 is not the UV-equipped MA-50 some old reviews describe.
For more help before you decide, start with the Medify air purifier complete guide, then check the room size guide if you're close to a boundary. If you already know your room is large, the large room air purifier picks are the better next step. And when you're ready to compare current pricing, check the MA-40 and MA-50 V3.0 on Amazon.
